Question

Which of the following is not true about the loop of Henle ?

• A. Primary function of the loop of Henle is recovery of water and sodium chloride from the urine.
• B. The descending loop of Henle is relatively impermeable to solutes and permeable to water.
• C. The ascending loop of Henle is permeable to solutes and is impermeable to water.
• D. The filtrate that moves out of the loop of Henle, is hyperosmotic compared to what entered the loop.

Answer 1

The correct option is D The filtrate that moves out of the loop of Henle, is hyperosmotic compared to what entered the loop.

The primary function of the loop of Henle is to reabsorb the bulk of water and NaCl in the filtrate and is actively pumped out as the filtrate moves through the ascending limb. The descending loop of Henle is relatively impermeable to solutes and is permeable to water. The ascending loop of Henle is permeable to solutes and is impermeable to water. NaCl is selectively absorbed and the filtrate that moves out of the loop of Henle is more dilute or hypoosmotic compared to what entered the loop, with about 25% of the NaCl that was in the filtrate having been absorbed.